*{
    margin: 0;
    padding: 0;
}
body{
    height: 100%;
}
html{
    height: 100%;
}
.four_four{
    width: 100%;
    height: 100%;
    position: fixed;
    top: 0;
    left: 0;
}
.four{
    position: absolute;
    top: 100px;
    left: 50%;
    transform: translateX(-50%);
    width: 900px;
    height: 300px;
    background-color: #ffffff;
    line-height: 300px;
    text-align: center;
    font-size: 250px;
    font-family: '华文彩云';
    color: #42BBFD;
}
.fourBtn{
    position: absolute;
    width: 240px;
    height: 60px;
    background-color: #42BBFD;
    top: 370px;
    left: 50%;
    transform: translateX(-50%);
    border-radius:20px ;
    transition: all 0.3s;
}
.fourBtn:hover{
    background-color: #ffffff;
    border: 1px solid  #42BBFD;
}
.fourBtn>a{
    width: 100%;
    height: 100%;
    display: block;
    color: #FFFFFF;
    text-align: center;
    line-height: 60px;
    font-size: 20px;
    cursor: pointer;
    transition: all 0.3s;
}
.fourBtn>a:hover{
    color: #42BBFD;
}